Thanks, Dick. It must have just been the club going for longest in the same place. From Topic's own web site -

The Bridge Folk Club in Newcastle was founded by Louis Killen and Johnny Handle in 1958, putting it in the same sort of ball-park era as the Topic. Its claim to longevity fame is that it has been in just one venue all its existence - apart from a 6-month gap for refurbishment of the pub - which the Topic certainly can't claim.

Just out of interest and keeping the thread afloat :-)